1, BK means controlling the lighting transformer, for example, BK-500VA means that the transformer capacity is 500VA. Transformers are used as control loops in electrical equipment, and as power sources for signal lamps, indicator lamps and low-voltage safety lamps;
2. Brand model of 2.BF circuit breaker. If the circuit breaker BFM6/ 1P, it means that the circuit breaker is 1P.
Low-voltage distribution system consists of distribution substation (usually reducing the transmission voltage of power grid to distribution voltage), high-voltage distribution line (i.e. voltage above 1 kV), distribution transformer, low-voltage distribution line (voltage below 1 kV) and corresponding control and protection equipment.
Extended data:
Reading method of electrical low-voltage wiring system diagram;
1, see main circuit steps.
2. Look at the electrical equipment in the main circuit. Electrical equipment refers to electrical appliances or electrical equipment that consume electric energy. First of all, we should see clearly how many kinds of electrical appliances there are, their categories, uses, connection methods and some different requirements.
3. Find out what electrical components are used to control electrical equipment. There are many ways to control electrical equipment, some are directly controlled by switches, some are controlled by various starters, and some are controlled by contactors.
4. Understand the control appliances and protection appliances used in the main circuit. The former refers to other control elements besides conventional contactors, such as power switch (transfer switch and air switch) and cam switch.
The latter refers to the specifications of short-circuit protection devices and overload protection devices, such as electromagnetic release and thermal overload release in air switches, and the uses and specifications of fuses, thermal relays and overcurrent relays. Generally speaking, after analyzing the main circuit as above, you can analyze the auxiliary circuit.
5. Look at the power supply. Need to know the power supply voltage level, whether it is 380V or 220V, whether it is from bus, distribution panel or generator set.
Baidu Encyclopedia-Low Voltage Wiring System